Gas Mileage (again)

[TaylorMade]

Sorry to mention this topic again, but my car's got me stumped. I filled up today, and found that my gas mileage is 13.8. What could I possibly do? What could be the cause of this? And ive already done the battery disconnecting trick. Does it have to be the negative cable? What should I do?

[Hooligan]

Use a "lighter" foot on the accelerator [:I]!! Not sure of what you have already tried. How many miles? Turbo or NA, have you changed plugs, wires?

I guess I have more ???'s than you do, but we need to have the answers to be able to help you. I'm sure you have posted this problem before, but rather than searching for your posting we need to know.

It is the negative cable that you disconnect. Leave it off 3-5 minutes.

[TaylorMade]

oh yeah sorry about that. 61,000 miles. N/A. Changed plugs and wires last week, upgraded to double plats and 8mm wires. I have lightened up on the accellerator. I also have a k&n air filter and an aftermarket muffler. I have heard, though, that the muffler could be a reason why. So the positive end disconnected wont reset the battery? Cause I did that, left it off for 10 minutes. The negative is a little bit tougher to get to

[VellianPT]

i just filled up today and only got 14 i have a 01 NA with a intake on it i just put on but my tires were low that may affect it plus i've been driving really hard in the city, but i hope my milage gets better cuz prices are going back up, i dunno what else you could do,, also whats the battery disconnect and reset suposed to do?

[TaylorMade]

it resets the pcm's learned fuel input. What should the tire pressure be? Ive got low pro tires if that makes a difference

[VellianPT]

stock is 34 psi check the tire it might say it there

[junkno]

i used to get very loooooow milage, about 125 miles driving hard. Then for a whole week, i tried not flooring it and keeping the rps under 2400. And what do u know, i got upto a 204 miles which is about 20 mpg . Try it man , u dont have to fill the car for a week (at least for me)

[TaylorMade]

ive tried it, my mpg went from 13 to 13.8

[Mean Green]

Something's going on because when I had the '01 auto I got 22-24 mpg with the MX-5 shift thing, Airade intake, Dynomax axleback exhaust and Eibachs. Now with my wife owning the '01 she pretty much gets 24 mpg all of the time. When I first got the '01 I was lucky to get 17 mpg. As it got older the mpg went up. The ]01 has 80,000 miles on it now. All of the mpg is with town, country highway and freeway driving. You must do a lot of in town, city driving. How does your PT run? Have you ever had the throttlebody cleaned? Have you asked the dealer or someone who knows fuel injected cars why your mpg is so low?

[TaylorMade]

no i havent had the throttle body cleaned or asked them. I actually just found out today how low it was. I knew it was low, but not ford expedition low. someone mentioned on another forum to get the pcm flashed at a dealership. what about that?